Night pay in, overtime out
Shift Differential Pay Calculator
A night shift that pays $2.00 more an hour changes two numbers, not one: what those hours pay at straight time, and what every overtime hour in the same week is worth. The second number is where checks go wrong, because the differential is not multiplied by 1.5 on its own — it is folded into the average rate that the 1.5× is applied to. This page does that arithmetic in the open, including the weeks where the two common payroll shortcuts give different answers.
The short answer
Yes — a shift differential belongs in the regular rate, so it raises the base the 1.5× is calculated on. It is not paid on top of overtime as a separate bonus. For $20.00 an hour plus a $2.00 night differential across a 45-hour week worked entirely on nights, the check is $1,045.00. The same week at $20.00 flat is $950.00, so the differential is worth $95.00 — $90.00 of straight time and $5.00 of extra overtime premium.
45 hours, all on nights — $20.00 base + $2.00 differential
Straight-time earnings = 45 × $22.00 = $990.00
Regular rate = $990.00 ÷ 45 hours = $22.00
Overtime premium = 0.5 × $22.00 × 5 hours = $55.00
Week total = $990.00 + $55.00 = $1,045.00
Where the differential actually enters the calculation
Under the Fair Labor Standards Act the overtime rate is one and a half times the regular rate, and the regular rate is all remuneration for employment — hourly wages, differentials, non-discretionary bonuses, commissions — divided by the hours worked, minus a short list of statutory exclusions in section 7(e) of the Act. A shift differential is pay for hours worked at a particular time of day. It is not on that exclusion list, so it goes into the numerator along with the base wages.
The consequence is easy to miss: the differential is never a separate 1.5× on the $2.00. It changes the average. Ninety dollars of differential spread across 45 hours is $2.00 an hour added to the average, and the half-time premium on the 5 overtime hours is computed on that average, not on the base rate alone.
The five-line method
- Add every dollar of straight-time pay for the week. Base rate × all hours worked, plus the differential × the hours that earned it, plus any flat weekly premium.
- Divide by total hours worked. That is the regular rate for the week.
- Count overtime hours. Past 40 in the workweek under federal rules, or past a daily threshold if your state has one.
- Overtime premium = 0.5 × regular rate × overtime hours. Those hours are already counted at straight time in line 1, so only the extra half is added here.
- Add line 1 and line 4. That is the gross pay for the week.
Some payroll systems skip the average and pay the overtime hours at 1.5 times the rate in effect for those hours. That is lawful whenever it pays at least as much as the method above, and it usually does when the overtime hours are themselves night hours. It falls short when the overtime hours are day hours and the differential was earned on other hours in the same week — shapes C and D below.
Four shapes of the same $2.00 in a 45-hour week
Straight-time earnings are $990.00, $910.00, $920.00 and $980.00 in A to D. Every row uses the same $20.00 base, the same 45 hours and the same 5 overtime hours; only the shape of the differential changes.
Shape B — the $2.00 is only on the 5 hours that happen to be overtime
Straight time = 40 × $20.00 + 5 × $22.00 = $800.00 + $110.00 = $910.00
Regular rate = $910.00 ÷ 45 = 20.2222
Overtime premium = 0.5 × 20.2222 × 5 = $50.56
Week total = $910.00 + $50.56 = $960.56
Three ways to get shape B wrong or right, all on the same week: ignore the differential when pricing the overtime and you pay $950.00 (short by $10.56); keep the differential in straight time but compute the half-time premium on $20.00 and you pay $960.00 (short by $0.56); pay those 5 night hours at 1.5 × $22.00 and you pay $965.00, which is $4.44 more than the federal floor and perfectly lawful.
Shape C — the differential is on 10 hours, the overtime is on 5 different hours
Straight time = 35 × $20.00 + 10 × $22.00 = $700.00 + $220.00 = $920.00
Regular rate = $920.00 ÷ 45 = 20.4444
Overtime premium = 0.5 × 20.4444 × 5 = $51.11
Week total = $920.00 + $51.11 = $971.11
This is the shape that makes the average matter. The 5 overtime hours are day hours at $20.00, so a payroll system that prices overtime off the rate printed on those hours pays 5 × $30.00 = $150.00 and finishes at $970.00, $1.11 short. Ignoring the differential altogether is worse: $950.00, $21.11 short. Only the half-time premium on the weekly average — 0.5 × 20.4444 × 5 = $51.11 — reaches $971.11.
What a differential is worth, in one line
The extra money a differential adds to a week
Extra straight time = differential × hours that earned it
Extra premium = 0.5 × (that extra straight time ÷ total hours) × overtime hours
Shape B: $2.00 × 5 = $10.00, plus 0.5 × ($10.00 ÷ 45) × 5 = $0.56 → $10.56
Shape C: $2.00 × 10 = $20.00, plus 0.5 × ($20.00 ÷ 45) × 5 = $1.11 → $21.11
Both match the totals above: $960.56 − $950.00 = $10.56, and $971.11 − $950.00 = $21.11
In a 40-hour week the second term disappears. There are no overtime hours for the average to reach, so $2.00 × 40 = $80.00 is the whole effect. The same $2.00 is worth $95.00 in a 45-hour week worked entirely on nights, because it also lifts the premium on five hours.
Differentials from $0.50 to $3.00 an hour
Same 45-hour week, all hours on nights, $20.00 base. The week is 40 hours at the night rate plus 5 at 1.5 times it, which is the same as 47.5 hours of straight time at that rate — a quick way to check any row.
Percentage differentials and two-tier shifts
A percentage differential is converted to dollars before anything else happens: multiply the base by 1 plus the percentage, and from that point it is an ordinary hourly rate.
15% night differential — $20.00 base, 45 hours all on nights
Night rate = $20.00 × 1.15 = $23.00
Straight time = 45 × $23.00 = $1,035.00
Overtime premium = 0.5 × $23.00 × 5 = $57.50
Week total = $1,092.50 — the same as a flat $3.00 differential at this base
Evening $1.50, night $2.50 — 30 day, 10 evening, 5 night hours
Straight time = 30 × $20.00 + 10 × $21.50 + 5 × $22.50 = $600.00 + $215.00 + $112.50 = $927.50
Regular rate = $927.50 ÷ 45 = 20.6111
Overtime premium = 0.5 × 20.6111 × 5 = $51.53
Week total = $979.03
With three rates in one week the average is the only thing that matters. The overtime hours carry a half-time premium on 20.6111 whether they were day, evening or night hours — which is why a payroll system that pays overtime at the rate printed on those specific hours can land on either side of the correct total.
What belongs in the regular rate, and what does not
- In: an hourly evening, night or weekend differential; a flat weekly shift premium; a percentage differential once converted to dollars; a non-discretionary production bonus; commission.
- Out (section 7(e) exclusions): gifts and discretionary bonuses; holiday, vacation and sick pay for hours not worked; expense reimbursements; contributions to benefit plans; premium pay for hours beyond 8 a day or 40 a week under a contract; contractual premium pay for work on a weekend or holiday outside your normal schedule.
- The safe direction: including a payment in the regular rate can only raise the overtime owed, never lower it. Leaving something out that belongs in is the expensive mistake.
- The state layer: a few states compute the regular rate under their own definition and add daily overtime thresholds. Your state labor office is the authority on whether one of those rules reaches your job.
What the three calculator sites leave out
We searched the text we captured from the three sites this project benchmarks against. Both calculator sites take a single “Regular Rate” input and multiply it by an overtime multiplier, which cannot represent a week where part of the hours earned a different rate.
Counts are case-insensitive occurrences in the page text captured from redcort.com, calculatorsoup.com and timecardcalculator.net, re-counted 2026-10-21. The “Regular Rate” input on both calculator sites is a single hourly figure; neither page offers a field for a differential rate.
Questions people actually ask
Night shift pays $2 more an hour — does that $2 go into the rate the 1.5× is calculated on?
Yes. The differential is part of the regular rate, so it raises the rate the half-time premium is computed on. In a 45-hour week at $20.00 base with $2.00 on every night hour, the regular rate is $22.00 and the week pays $1,045.00. If only 5 of the hours were night hours, the regular rate is 20.2222 and the week pays $960.56 — not $950.00, which is what you get by ignoring the differential when pricing the overtime.
Is a shift differential included in the regular rate?
Yes, for FLSA purposes. The regular rate is all remuneration for employment divided by hours worked, less the specific exclusions listed in section 7(e) of the Act, and a differential paid for working particular hours is not one of them. The Department of Labor's interpretations of the regular rate are in 29 CFR Part 778.
How do I calculate overtime with a night differential?
Total the straight-time pay at every rate, divide by all hours worked to get the regular rate, then add 0.5 × that rate × the overtime hours. Shape C is the test case: 35 day hours, 10 night hours and 5 day hours past 40 pay $920.00 at straight time, a regular rate of 20.4444, a premium of $51.11 and $971.11 for the week. Paying the overtime at 1.5 × $20.00 instead finishes at $970.00.
What if the differential is a flat weekly amount rather than per hour?
It still belongs in the regular rate. A $80.00 weekly night premium on 45 hours at $20.00 gives straight-time earnings of $980.00, a regular rate of 21.7778, a premium of $54.44 and a week total of $1,034.44. Leaving the $80.00 out of the rate and adding it to the check afterwards pays $1,030.00, $4.44 short.
Is a shift differential required by law?
No. Federal law does not require extra pay for evening, night or weekend hours; a differential exists because a handbook, a union agreement or a state rule creates one. Once it is paid, though, it enters the regular rate and the overtime calculation above applies to it.
Does the differential apply to holiday or PTO hours I do not work?
No. A differential is paid for hours worked at that time, so it does not attach to holiday or PTO hours you did not work, and those hours are excluded from the regular rate because they are not hours worked. If you do work the night of a holiday, the hours you work earn the differential and count in the average like any other hours.
Related pages
Overtime calculator — split a workweek across a threshold
The weekly split at one rate. Its own page says it cannot handle shift differentials — this page is the arithmetic for the weeks where that matters.
Time and a half calculator — the 1.5× tier from a single rate
Rate, hours, and the premium hours priced separately. Use it once you know which rate the week actually carries.
Holiday pay calculator — four policy shapes for one shift
Holiday premiums stack on top of the regular rate the same way a differential does, and a night differential raises the holiday hours too.